New findings suggest that dogs possess the remarkable ability to process auditory information even while in the deepest stages of sleep, according to a small pilot study conducted on 13 canines. This study sheds light on the intriguing possibility that our furry companions might be attuned to our voices even during their slumber.
Researchers from Eötvös Loránd University, led by ethologist Huba Eleőd, conducted the groundbreaking study, which represents the first evidence of complex auditory processing during sleep in dogs. The study participants, a group of cooperative dogs, were fitted with devices that measured their event-related potential brain wave responses. They were then exposed to various vocalizations, both from dogs and humans, while in different states of wakefulness.
The auditory stimuli, including sounds such as yelps, whines, growls, coughs, laughter, sighs, and yawns, were played at consistent volumes and durations of approximately one second each. Notably, no jarring or negative sounds were used to avoid startling the dogs from their slumber.
Remarkably, the study observed that even during non-REM sleep, the dogs displayed an ability to differentiate between vocalizations originating from other dogs and those from humans. Furthermore, they seemed capable of discerning the emotional valence of the communication, distinguishing between positive and neutral tones.
The phenomenon of processing social cues during sleep has also been observed in primates, including humans, as well as certain non-primate species like mice. This capacity to interpret auditory signals during sleep is considered crucial for mammalian survival, given the substantial portion of time that mammals spend asleep.
The extent of comprehension during slumber depends on both the sleep stage and the nature of the sounds experienced. This aligns with human experiences, where names and specific sounds elicit unique responses even during sleep.
Dogs, like humans, rely on sleep for memory consolidation and emotional processing. As domestication has altered their sleep patterns, dogs now share sleep characteristics more closely with humans than with other laboratory species. Aging dogs, like humans with dementia, often experience shallow and interrupted sleep.
While further research is required to validate these findings, they add to the growing body of evidence highlighting similarities between canine and human sleep behavior. This research underscores the potential utility of dogs as subjects in comparative neurobiology studies, further expanding our understanding of both canine and human cognition during sleep.
